Sealing structure in a waterproof watch

ABSTRACT

A water-tight seal in a watch results from radial compression of a synthetic resin gasket between a portion of the case-back and the interior of the case-body. The gasket may also serve to mount the watch mechanism within the case-body.

United States Patent Fukushima 1 Dec. 19, 1972 [54] SEALING STRUCTURE INA [56] References Cited WATERPROOF WATCH FOREIGN PATENTS R APPLICATIONS[72] Inventor: Takekazu Fukushirna, Kamiina-gun,

Nagano-ken Japan 353,686 /]961 Switzerland ..8/90 R 721,920 l/l955 GreatBritain... .....58/90 R [731 Asslgneei Kablshiki 5mm, 904.290 8/1962Great Britain ..58/90 R Tokyo Japan 472,719 6/1969 Switzerland ..ss/90 R[22] Filed: Nov. 24, 1971 Primary Examiner-George H. Miller, Jr. [21]Appl' Attorney-Alex Friedman et al.

[] Foreign Application Priority Data [57] ABSTRACT 1970 Japan 1772\ Awater-tight seal in a watch results from radial com- Nov. 28, 1970 Japan..45/l17722 pre ion of a synthetic resin gasket between a portion of thecase-back and the interior of the case-body. [52] US. Cl. ..S8/90 R Thegasket may also Serve to mount h watch [51 Int. Cl. ..G04b 37/08mechanism within the d [58] Field of Search ..58/ R. 94, 88 C 1 Claim, 4Drawing Figures SEALING STRUCTURE IN A WATERPROOF WATCH BACKGROUND OFTHE INVENTION Conventionally, a case-back is sealed to a case-body bycompressive forces in an axial direction. Snap-action is necessary tohold the case-body and the caseback together. For this type ofstructure, tolerances must be very close, resulting in a relatively highreject rate in manufacture and consequently, increased cost. Moreover,it is conventional to include an annulus which seats upon the gasket andwhich serves to mount the watch mechanism within the case-body.

SUMMARY OF THE INVENTION An improved method of sealing a case-back to acase-body in a waterproof watch utilizes a synthetic resin gasket orpacking between an exterior cylindrical surface of the case-back and aninterior cylindrical surface of the case-body, the dimensions being suchthat the gasket is compressed radially, thus ensuring water tightnessbetween the case-back and the case-body. Moreover, the gasket may be soshaped that it mounts the watch mechanism securely within the case-body.Using a gasket of the type described, the aforementioned annular ringfor support of the watch mechanism is rendered unnecessary, thusdecreasing the number of parts involved in the sealing structure andmounting structure and the size of the watch may accordingly bedecreased with enhanced appearance of the watch.

Accordingly, an object of the present invention is to provide a sealingstructure for a waterproof watch in which the necessary seal is achievedby means of radial rather than axial compression.

Another object of the present invention is to provide a reduction in thenumber of parts necessary for effecting the sealing structure and formounting the watch mechanism within the case-body.

A further object of the invention is to provide a sealing structurewhich makes possible a reduction in the overall size of the watch andwhich enhances the appearance of the watch.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

The invention accordingly comprises an article of manufacture possessingthe features, properties, and the relation of elements which will beexemplified in the article hereinafter described, and the scope of theinvention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of theinvention, reference is had to the following description taken inconnection with the accompanying drawings, in which:

FIG. 1 is a sectional view of a conventional watch which depends oncompression in an axial direction for sealing the case-back to thecase-body;

FIG. 2 is a sectional view of a watch in accordance with the presentinvention wherein sealing between the case-body and the case-back isachieved by means of radial compression of a gasket;

FIG. 3 is a sectional view of a conventional watch in which sealing isachieved by means of axial compression and in which the gasket is usedto position a member which holds the watch mechanism within thecase-body; and

FIG. 4 is a sectional view of a watch in accordance with the presentinvention in which scaling is achieved by means of radial compressionand in which the gasket also serves to mount the watch mechanism withinthe case-body.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Where sealing between acase-body and a case-back is achieved by means of axial compression of agasket, a preferred method of holding the case-body and the case-backtogether is by means of snap-action. A conventional watch of this typeis illustrated in a sectional view in FIG. 1. Here, case-body 11 is heldto case-back 12 by means of snap-action and is sealed to case-back 12 bymeans of gasket 13 within groove 14. The snapaction referred to takesplace at contact surface 15 between case-back l2 and case-body 11. Sealof gasket.

13 to case-back 12 is effected at surface 16. As aforenoted, tolerancesmust be held very closely to ensure that the various members involved inthe sealing structure will hold together and will effect a suitableseal. It will further be noted that case-back 12 extends outward beyondgasket 13 and has a skirt 17 which seats against case-body 11 at thesurface 18. The case-back l2, consequently, must extend well beyondgasket 13.

In contrast, the case-back of the present invention is sealed to thecase-body by radial compression. This is illustrated in FIG. 2 wherecase-body I9 is sealed to case-back 21 by radial force exerted againstgasket 22. The sealing surfaces are 23 and 24. Sealing surface 23 is theexterior surface of rim 25 and sealing surface 24 is an interior surfaceof case-body 19. As can be seen, the diameter of exterior surface 26 ofcase-body 19 is small relative to the diameter of case-body II of theconventional watch. Moreover, tolerances are no longer critical sincesnap-action is not involved, and the diameter of the case-back issubstantially decreased over what it is in a conventional watch.

The conventional watch shown in FIG. 3 differs from that in FIG. I inthat an annular ring 29 seats on gasket I3 and serves as a mount forwatch mechanism 27 within case-body 11.

In the embodiment of the present invention shown in FIG. 4, seal betweenthe case-body l9 and the caseback 21 is effected by radial compressionof gasket 22. In this embodiment, gasket 22 extends axially into aportion 28 which serves the same function as annulus 29 in aconventional watch. In this way, gasket 22 having portion 28, and madeof compressible, deformable, synthetic resin serves the double functionof sealing a case-back to a case-body and mounting a watch mechanismwithin a case-body. Moreover, tolerances of manufacture are not socritical. The number of parts necessary is smaller, both the case-backand the casebody may be smaller in diameter and protection of watchmechanism 27 is provided by the fact that gasket 28 is deformable. Thefact that the case-body and caseback are smaller enhances the appearanceof the watch. Also brim 31 extends beyond rim 25 and gasket 22 andserves to locate case-body 19 in the axial direction.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above construction withoutdeparting from the spirit and scope of the invention, it is intendedthat all matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not inalimiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebctween.

What is claimed is:

l. A sealing structure of a water-proof watch comprising a case-back, arim integral with said case-back and having an exterior surface, acase-body having an interior surface and a gasket compressed radiallybetween said exterior surface of said rim and said interior surface ofsaid case-body wherein said case-back has a brim extending radiallybeyond said rim, said case-body being seated directly on said brimthereby precisely locating said case-back axially with respect to saidcase-body and the watch movement, said watch movement being insertableinto and removable from said case-body through the rear of said watch,said gasket serving'as a mount for said watch movement.

I! I l k

1. A sealing structure of a water-proof watch comprising a caseback, arim integral with said case-back and having an exterior surface, acase-body having an interior surface and a gasket compressed radiallybetween said exterior surface of said rim and said interior surface ofsaid case-body wherein said case-back has a brim extending radiallybeyond said rim, said case-body being seated directly on said brimthereby precisely locating said case-back axially with respect to saidcase-body and the watch movement, said watch movement being insertableinto and removable from said case-body through the rear of said watch,said gasket serving as a mount for said watch movement.